Improvement in safety-valves



R. RUDD.

SAFETY VALVE.

Patented MaylG, 1876.

] Un r'rnn STATES- PATENT Gnrrcn.

ROBERT RUDD, 0F ALEXANDRIA, VIRGINIA, ASSIGNOR on ONE-HALF HIS RIGHT TO JAMES E. WADDEY, OF SAME PLACE.

IMPROVEMENT IN SAFETY-VALVES.

Specification forming part of Letters Patent No. 177,564, dated May 1 6, 1876; application filed April13, 1876.

To all whom it may concern: A

Be it known that I, ROBERT Rum), of Alexandria, in the county of Alex'andriaand State of Virginia, have invented a new and useful Improvement in Safety-Valves; and I do here by declare that the following is a full and exact description of the same, reference being had to the accompanying drawings, and to the letters'of reference marked thereonr This invention consists mainly, first, in the special construction of the valve proper, it being provided with a projecting flange or lip located above its seat, by means of which a pocket or chamber is formed when the valve is seated, so that when the valve is lifted the pressure of the escaping steam is employed to raise it still higher, in order that the boiler may be rapidly relieved and the valve quickly shut down second, in the combination, with this peculiarly-constructed valve, of a valvecup having inclined sides, the construction being such that by the continued movement of the valve when lifted the area of the discharge-opening is constantly increased; and,

third, in the special construction of certain and use my invention, 1 will now proceed to describe fully its construction and manner of operation.

A represents the constructed. generally of any proper form, and be provided with the usual or other proper means for attaching it to the boiler. It is essentially provided, however, with a seat, a, a

recess, a, and the inclinedor tapering surface a as shown.

B represents the valve, which may be constructed generally of any proper form, but is essentially provided with the seat I) and recess 1), formed by the projecting lip or flange b as shown. When the valve rests upon its seat in valve-cup, which may be.

the cup the pocket or chamber as is formed below the lip or flange, as shown.

0 represents the pressure-spring, arranged in the usual well-known or other proper manner. I

The operation of the valve is as follows: When the pressure in the boiler exceeds the pressure of the spring the valve is, of course, lifted from its seat, and the steam, consequently, escaping through the opening, and filling the pocket or chamber or, acts expansively and directly upon the lip 0 and aids in lifting the valve still higher, so that the area of the discharge-opening is increased.

It will be understood that when the ordinary valve is used the pressure of the steam simply raises the same a short distance, the resistance of the spring increasing as the valve is raised, and that, consequently, a small discharge-opening is furnished for the-delivery of the steam, and hence the boiler is slowly relieved. When my improved valve is used, on the other hand, the escaping steam itself exerts a pressure, and, in connection with the normal boiler-pressure, raises the valve sufficiently high to relieve the boiler with great rapidity.

It will be. understood that, in consequence of the inclined surface of the cup, the area of the discharge-opening is rapidly increased as the valve is lifted, the valve rising in a vertical plane, and consequently leaving a space of constantly-increasing width in its upward movement. 7

The locking device will now be described: D D represent studs or bolts connecting the cup with the spring -bar E, in the usual well-known manner. 0 0 represent the adjusting-nuts, by means of which the amount of pressure exerted by the spring is determined. F represents a bar, provided at its ends with cups or sockets ff, adapted-to fit over and inclose the adjusting-nuts, as shown. GG represent headed pins extending through the spring-bar E and locking-bar E, which are provided above with openings adapted to receive the sealing-wire g, as shown.

The operation will be readily understood. The nuts having been properly adjusted, the

cap bar is put in p sition and secured by the pins and sealing-Wire, so that no change can be made without the certainty ofdetection.

The construction of the valve as a whole is exceedingly simple, and yet it is very effective in its action.

Having thus fullyde'scrihed my invention, what I claim as new, and desire to secure by Letters Patent, is-

The valve B, having the projecting lip or flange N, in combination with the valve-cup,

having the'cylindrical portion a and taperin ,9;

portion M, the construction being such that the valve must move some distance to clear the cylindrical portion of the valve-cup, as described.

This specification signed and witnessed this 6th day of April, 187

ROBERT RUDD. Witnesses:

WM. FLEMING, CHARLES E. STUART. 

